<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view scroll-y="true" class="left-scroll-view" :style="{height:wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view scroll-y="true" class="right-scroll-view" :style="{height:wh + 'px'}" :scroll-top="scrollTop">
       <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <!-- 分类标题 -->
          <view class="cate-lv2-title">{{item2.cat_name}}</view>
          <!-- 商品列表 -->
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3">
               <image :src="item3.cat_icon" class="cate-lv3-item-img"></image>
               <text>{{item3.cat_name}}</text>
            </view>
            
          </view>
         
       </view>
        </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar高度
        wh:0,
        //分类数据列表
        cateList:[],
        //当前选中的索引，默认值为0
        active:0,
        //二级分类列表
        cateLevel2:[],
        //滚动条距离顶部距离
        scrollTop:0
      };
    },
    onLoad() {
      // 获取当前系统的信息
      const sysInfo = uni.getSystemInfoSync();
      // 为 wh 窗口可用高度赋值
      this.wh = sysInfo.windowHeight -50;
      // 调用获取分类数据的方法
      this.getCateList();
    },
    methods: {
      //获取分类数据的方法
      async getCateList(){
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        console.log(res)
        if(res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        //为二级分类赋值
        this.cateLevel2 = res.message[0].children
      },
     //点击左侧菜单项时触发
      activeChanged(i){
        this.active = i
        //为二级分类赋值
        this.cateLevel2 = this.cateList[i].children
        //让scroll-view滚动到指定位置
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
  }
  }
</script>

<style lang="scss">
  .scroll-view-container{
    display: flex;
    .left-scroll-view{
      width: 120px;
      height: 100%;
      .left-scroll-view-item{
        line-height: 60px;
        background-color: #f7f7f7;
        text-align: center;
        font-size: 12px;
        //激活项的样式
        &.active{
          background-color: #ffffff;
          position: relative;
          &::before{
            content: '';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            top: 50%;
            left: 0;
            transform: translateY(-50%);
            }
        }
      }
    }
    .right-scroll-view{
      height: 100%;
      flex: 1;
      background-color: #fff;
      .cate-lv2-title{
        font-size: 12px;
        font-weight: bold;
        text-align: center;
        padding: 15px 0;
      }
      .cate-lv3-list{
        display: flex;
        flex-wrap: wrap;
        .cate-lv3-item{
          width: 33.33%;
          display: flex;
          flex-direction: column;
          align-items: center;
          justify-content: center;
          margin-bottom: 10px;
          font-size: 12px;
          .cate-lv3-item-img{
            width: 60px;
            height: 60px;
          }
          text{
            margin-top: 12px;
          }
        }
      }
    }
  }

</style>
